Tamper-indicating threaded plastic closures have found widespread acceptance in the marketplace for use on containers for beverages and food products, as well as for non-food items. One particularly commercially successful construction is disclosed in commonly-assigned U.S. Pat. No. 4,418,828, to Wilde et al., which closure can be efficiently formed in accordance with the teachings of U.S. Pat. No. 4,497,765, to Wilde et al. A modified form of this tamper-indicating closure is disclosed in U.S. Pat. No. 5,004,112, to McBride.
A tamper-indicating plastic closure embodying the teachings of the above patents includes an upper closure cap, and an annular pilfer band depending from a skirt portion of the closure cap. The pilfer band is either partially or completely detachably connected to the skirt portion by a series of circumferentially spaced frangible bridges. For those applications where it is desired that the pilfer band be completely detached from the closure cap during closure removal, the closure typically functions such that the annular pilfer band remains on the neck of the container. In contrast, for some applications, particularly in the case of returnable and reusable containers, it is desirable that the pilfer band be only partially detached from the closure cap attendant to closure removal, with the pilfer band remaining joined to the skirt portion of the cap. Use in this manner desirably avoids the need to remove the annular pilfer band from the container for its reuse.
For those applications where it is desired that the pilfer band remain connected to the closure cap after closure removal, closures of the type disclosed in the above-referenced patents include two particular features. First, the closure is provided with a connector portion which joins the pilfer band to the closure skirt after the frangible bridges fracture during closure removal so that the pilfer band is otherwise detached from the closure cap. Additionally, such closures include a fracturable region in the annular pilfer band itself, which region is typically positioned in the vicinity of the connector portion. By this arrangement, closure removal not only results in the desired partial separation of the pilfer band from the closure cap, but further results in splitting or fracture of the band itself, with the band assuming a curl-like configuration (sometimes referred to as a "pigtail").
Experience has shown that consumers sometimes separate and break the connector portion which joins the partially detached pilfer band to the closure cap, and rather than dispose of the now-separated pilfer band, insert it into the associated container. Unfortunately, this can undesirably inhibit efficient reuse of the container, since the dimensions of the typical pilfer band are such that it cannot be removed from the container by the usual automatic washing equipment.